I was set on a 2500, but now considering a 3500

IdoMRI · January 23, 2020

Here's my 2500

FirstAscent · January 23, 2020

Here's my 2500

Ok so the 3500 has a helper spring on top of the main lead spring. I wonder if the main portion of the spring is the same spring rate as the 2500 and then the helper makes up the difference for the additional payload

Unloaded, the first stage spring rate is equal between the two but the second stage engages quicker.

Is the first stage the main spring and the second stage the helper spring? Is that what you were referring to?

MORSNO · January 23, 2020

The easy visual is 2500 has a lower overload spring only, 3500 has the upper overload springs added in adaption to the lower.

MORSNO · January 23, 2020

3 minutes ago, FirstAscent said:

Ok so the 3500 has a helper spring on top of the main lead spring. I wonder if the main portion of the spring is the same spring rate as the 2500 and then the helper makes up the difference for the additional payload

The main spring pack is the same, they are the same width and thickness 4 springs with lower overload. The only difference is the upper overload springs.

MTU Alum · January 23, 2020

10 hours ago, MORSNO said:

The main spring pack is the same, they are the same width and thickness 4 springs with lower overload. The only difference is the upper overload springs.

That's not completely correct. The first stage (four spring pack) is the same but the second stage (bottom spring) engages about 1 inch sooner on 3500 and is different rate. The 3500 also has the third stage (above the main spring pack).

#iworkforGM

ShotgunZ71 · January 23, 2020

I have a 2500HD High Country that I pull my 14,300 lb 5th wheel with. If I were to go diesel, I'd have to step up to a 3500HD due to the reduced payload the diesel results in. My current payload is 3245.

CRApex · January 24, 2020

22 hours ago, ShotgunZ71 said:

I have a 2500HD High Country that I pull my 14,300 lb 5th wheel with. If I were to go diesel, I'd have to step up to a 3500HD due to the reduced payload the diesel results in. My current payload is 3245.

The GCWR (max vehicle weight with a loaded trailer) is 27500 with the 2500 diesel SRW Crew and max trailer of 18500lbs so you would still be ok with your trailer. Diesel payload on the 2500 is 3043 so you would have to put the extra cooler of beer in the trailer if you're loading the truck right to the max...lol

I agree though, makes more sense to just get the 3500.

jjackkrash · January 24, 2020

Pin weight on a 14k fifth wheel + hitch could easily exceed the 3k payload capacity on a 2500 by itself. It is nice to have a little cushion.

MTU Alum · January 24, 2020

The SAE trailer ratings are determined by 15% pin load for GN/fifth wheels and 10% tongue for conventionals. If your trailer is higher than this, you will need to lower trailer weight because you maybe over RGAWR and/or GVW.

#iworkforGM

jjackkrash · January 24, 2020

I have seen pin weight recommendations that range from 15 to as high as 25% for fivers. Only way to know for sure is to weigh it.

ShotgunZ71 · January 24, 2020

The truck and camper is 21,800 loaded up as we travel. The truck's GCWR is 24,000 and max gooseneck/5th wheel weight of 16,600. My 5th wheel is a couple thousand lbs less how we travel. We don't tow with full tanks, etc. Hence, if I were to go to a diesel, I'd get a 3500 for the extra capacity and not be at or over the limits.

es2020HD · January 28, 2020

On 1/24/2020 at 1:17 PM, MTU Alum said:

The SAE trailer ratings are determined by 15% pin load for GN/fifth wheels and 10% tongue for conventionals. If your trailer is higher than this, you will need to lower trailer weight because you maybe over RGAWR and/or GVW.

#iworkforGM

So I haven't seen it specifically stated yet....Is it possible to get the spring pack that the 3500 uses (or something aftermarket) to give the 2500 more carrying capacity? I'm about maxed out with my 5th wheel pin weight and would love some cushion in case I load my trailer differently. I test drove the 3500 at the same time as the 2500 and liked the ride in the 2500 better. But at the time, I didn't realize I would be so close to max RGAWR. I'm well within my GCWR, but never thought about how much of that weight would be on the bed. I bet I'm not the only one!

MTU Alum · January 28, 2020

33 minutes ago, es2020HD said:

So I haven't seen it specifically stated yet....Is it possible to get the spring pack that the 3500 uses (or something aftermarket) to give the 2500 more carrying capacity? I'm about maxed out with my 5th wheel pin weight and would love some cushion in case I load my trailer differently. I test drove the 3500 at the same time as the 2500 and liked the ride in the 2500 better. But at the time, I didn't realize I would be so close to max RGAWR. I'm well within my GCWR, but never thought about how much of that weight would be on the bed. I bet I'm not the only one!

It depends on the model of truck you have. The frames are different between 3/4 and one tons on crew cab standard box models where they don't have the nuts in the frame to accept the overload brackets. Without the overload brackets, the one ton leaf springs don't do you much good.

Increasing your tire pressure from 70 to 80 psi will increase your load capability on your rear axle from 6600 to 7250 lbs. If you desire more spring rate, an aftermarket air spring could be a solution. I would caution that adding an air spring to a suspension that was not designed for one can be dangerous if you run too much air pressure.

#iworkforGM

es2020HD · January 28, 2020

12 hours ago, MTU Alum said:

It depends on the model of truck you have. The frames are different between 3/4 and one tons on crew cab standard box models where they don't have the nuts in the frame to accept the overload brackets. Without the overload brackets, the one ton leaf springs don't do you much good.

Increasing your tire pressure from 70 to 80 psi will increase your load capability on your rear axle from 6600 to 7250 lbs. If you desire more spring rate, an aftermarket air spring could be a solution. I would caution that adding an air spring to a suspension that was not designed for one can be dangerous if you run too much air pressure.

#iworkforGM

Excellent information, MTU Alum! I wasn't aware of the tire air up option. Is that documented anywhere that you are aware of?

On the overload brackets, I have the 3/4 ton Denali HD diesel so I assume that means I don't have the nuts. Is that something that a welding shop could easily add? Are the holes already there in the frame for the bolts to pass through?

BTW, hoping this is not considered hijacking the thread, but I think this info could be useful to other 2500 owners or 'would be' owners that later wished they had more payload capacity. I checked into upgrading to the 3500 SRW to avoid this, but the hit on trade in was atrocious.